Blower



June 21, 1955 J. B. BURROWES BLOWER 2 Sheets-Sheet 1 Filed Dec. 14, 1949ATTO R N EYS June 21, 1955 J. B. BURROWES BLOWER 2 Sheets-Sheet 2 FiledDec. 14, 1949 ATTOR N EYS United States Patent F BLOWER John B.Burrowes, Dayton, Ohio, assignor to. The hair Blower Company, Dayton,.Ohio, a corporation of Ohio Application December, '1949, semi No,132,931 f sclaimsf. "(Clliwlilfl) This invention relatesto blowers andmore particularly to a centrifugal blower and the drive therefor.

Centrifugal blowers suchias are used in hot' air' heat ing systems,ventilating systems andithe likej'embody a blower wheel mounted: foroperation in-ahousing and driven by means. of a motor which is commonly.supported on the housing and'connected to the wheelthrough belts andpulleys. Such a device usually :requires "afractional horse power motorfor drivingpurpos'esiin order to have available the. necessary'minimun'istarting' torque required to start the blower'wheel throughthe belt and pulley drive and-to overcome the inertia of the system.Ordinarily the powercapacity of "such a motor has not been effectivelyutilized.underrunning-condhJ tions, and the use of this type'of motorhas therefore been uneconomical as to 'size, weight, and ei'rp ens'e.

In accordance with the present invention a blower construction isprovided in which the blower wheel'is directly carried on the motorshaft'with the motor being located adjacent and projecting partiallyinto the inlet at one end of the blower housing, and the motor'andhousing are separately mounted on a common base=to assure adequate flowof air' to "and through'the inlet effective and advantageous coolingaction is obtained so" that a relatively low power and inexpensivefan-type commutators may'beused.

It is further a feature of the invention'that with'such a motor havingthe inherent characteristic of reduction in speed on increased load, themotor does not t'endto overload and will drop 'in-spe'ed as theresistanceto the motor Without starting' switcheis, centrifugalcut-outs'or delivery of the air from the blower is redu'c'e'clf'andhence the output of the blower is decreased, thus: avoiding possibledamage to the motor from an excessive load condition. In addition, thespeed of the motor is readily controlled by the incorporation therewithof afyari a ble reluctance choke coil having the effect of reducing thevoltage applied to thernotor, and thus a 'simpleand highly satisfactorycontroland variation in the "motor speed is obtained.

Where embodied in a double inlet blower, the 'en tire assembly isproperly balanced and correlated through the provision of a double inletwheel in which thetwo portions of the wheel are of unequal s ize,,suchthat their outputs will-be balanced throughout their length and thecreation of turbulence and loss of output are thereby avoided. It isfurther desirableto provide the smaller sized wheel on the side adjacentthe motor with the Patented June .21, 1955 larger sized wheel on theopposite side, and with both sides of the blower housing kept free ofbrackets or other supports by "the separate-mountings for the motor andhousing, minimum obstruction of the entry of the air from'either side isassured and desirable output charaet'eristics obtained.

It is accordingly oneof the principal objects of the present-inventionto provide a blower assembly of simple and compact construction whereinthe blower wheel is mounted directly on the shaft, of the motor, and themotor and blowerv housing are separately mounted on a common base insuch manner that the motor is. supported inthe path .of the. air flowinginto the blower for effective cooling'without undesirably obstructingthe proper .flow' of--airqthrough the inlet.

Another "object is to provide a double inlet blowerassembly wherein thedrive motor which directly supports :the double inlet wheel is mountedto extend into one'ofthe inlets in the blower housing and wherein thetwo parts of the wheel are of unequal size and are substantiallybalanced so that their outputs are comparable throughout theirrespective lengths. i

It is also an object of'the invention to provide a blower assembly whichincludes a' relatively small and economical'shaded pole drive motorwhich is directly connected to the blower wheel and has suflicienttorque to start and run the wheel and likewise is adapted for variablespeed ner.

Other objects and advantages of the invention will beapparent from thefollowing description, the accompany-- ing drawings and the appendedclaims. I In the drawings- Fig. l is a p'erspective'view showing ablower assembly in accordance with the invention;

i Fig. 2 is a perspectiveview of the assembly' taken from a differentangle and with the blower housing removed; Fig. 3 is a view similar toFig. 2 with the blower wheel removed; a

Fig. 4 is a view of the assembly partly in side elevation:

and 'partly broken away in vertical section; and

Fig. 5 isan enlarged view of a fragment of Fig. 4.-

Referring to"the drawings, which'illustrate a preferred embodiment ofthe invention, the base of the assembly: 7

is shown as' f ormedof sheet metal, and it comprises a main centersection 11, don'wardlyturned side flanges 12 and outwardly turned edgeflanges 13. The corners of the flanges 13 are shown as provided withrubber grommets 15 which serve as feet for supporting the as-' semblyupon a table or other horizontal surface. A housing for the blower wheel22 is mounted directly' on the center portion l l 'of the base 10 as bymeans "of bolts and nuts 23, and rubber washers 24 may beem: ployed asshown to cushion this connection between the housing and base. Thehousing includes inwardly turned portions at either end which define theinlets 25 and 26 for thewheel, and wheel.

The housing 20 is shorterfrom end to end than the base 10, and it ismounted at one end of the base to leave space for'the fra'me whichsupports the drive motor 33, which is mounted at the opposite end of italso includes the outlet 27 for the base 10 from housing 20 in spacedrelation with the housing. As shown, the frame 30 includes side flanges34whichfit rover. andare -welded or otherwise secured to g the. flangeportions12 of the base, and the forward edges of theselside flanges '34are inclined as shown to provide portions of maximum width at the lowerend of the frame which "seat on the flange portions 13of the base.

Thelower end of frame 30 includes a flange 35 which is folded under thebase portion 11 and cooperates with the side flanges 34 to reinforceframe 30 against bending operation in a simple and readily controllableman or sagging towards the base under the weight of the motor and blowerwheel. y

The motor 33 is provided with boss portions 40 at each end thereof, andthe frame is formed with a socket 41 adapted to receive the boss at theouter end of the motor. As shown in Fig. 5, a sleeve 42 of rubber isprovided as .a lining between theboss 40 and socket 41 to cushion themotor, and the outer end of the socket is turned inwardly at 43 to holdthis sleeve in place. The inner end of the motor is supported by abracket 44 of generally U-shape which includes a socket 45 at itscentral portion for receiving the other boss portion 40 of the motor.This socket also is provided with a rubber sleeve 42 and is turnedinwardly at its end to retain this sleeve in place. a

The outer ends of the bracket 44 are flanged at and nuts 47, and it isdesirable to proportion the parts in such manner that when the bolts andnuts 47rare drawn up tight to clamp the flanges 46 against frame 30, theinner ends of the rubber sleeves 42 will be com: pressed as shownbetween the motor and the frame 30 and bracket 44 respectively, in orderto assure a firm mounting for the motor with minimum vibration and noisein use. The bracket is arranged with its side per: tions vertical, andthese side portions are of increasing width in the direction of theframe 30 to give increased rigidity and thus to assure that the motorand its drive shaft 50 will be firmly supported in cantilevered-poshtion overhanging and substantially parallel with the base 10.

The blower wheel 22 is of the double inlet type, and

it is shown as formed of a pair of single inlet wheels.

51 and 52 each including a disk 53 at one end supporting a hub 55 andwith these disks 53 arranged in contact at a position intermediate theends of the resulting composite wheel. For example, satisfactory resultsha e been obtained with two single inlet wheels 51 and 52 constructed bywelding their component parts as; doscribed in copending application ofCarl E. William Serial No. 735,163, filed March 17, 1947, now Pat-,No.2,628,769 of February 17, 1953 and assigned to the same assignee as thisapplication, and with these wheels mounted in back to back relation asshown. Theh'ubs 55 of wheel 22 are mounted directly on the motor shaft50 in close relation with the motor 33 such that the motor and thebracket 44 project through the inlet 25 and partly into the interior ofthe adjacent'wheel portion 51. Since, therefore, the inlet 25 has lesseffective area than the inlet 26, it has been found desirable, tooonstruct the wheel with its two portions of correspondingly ditferentsize and capacity in order to obtain effective balance of the output ofthe Wheel throughout-its length, the wheel portion 52 being shownassubstam tially greater in axial length than the wheel portion 51.

The sizes of the two portions oi the blower wheel are correlated inaccordance with the desired, propertions and capacity of the blowerasernbly as a whole. Considering each portion of the Wheel as a singleinlet wheel, preferred results in operation are obtained when the lengthof the wheel is approximately onerhalf its diameter, and since the inlet26 is entirely open, the wheel portion 52 can be constructed to meetthese proportions, satisfactory results having beenohtained with thiswheel portion approximately 4 inches in length and 7 inches in diameter.Then if the inlet 25- is 7 inches in diameter and the motor 33 isapproximately 5% inches in diameter, satisfactory balance is obtainedwith the wheel portion 51 of the same diameter as wheel portion 52 and 3inches in axial length, eachwheel portion drawing air in through its owninlet and the disks 53 blocking the flow from one end of the wheel. tothe other.

The capacity of the motor 33 may be selected in ac: cordance with theproportions of the blower wheel, and with the wheel of the dimensionsgiven above and 46 for ready connection to the frame 30 by means ofbolts mounted directly on the motor shaft, highly satisfactory resultshave been obtained with a shaded pole motorSfi.

Such a motor has adequate starting torque to overcome the low startinginertia of the system, and since it has a drooping speed characteristic,i. e., the inherent characteristic of reduction in speed on increasedload, it does not tend to overload and will drop in speed as resistanceto the delivery of the air to the blower is reduced. The speed of such amotor is readily controlled by means of a variable reluctance chokecoil, which is' shown at 60 as mounted on the inside of frame 30 andprovided with a control knob 61 for ready manual adjustment of the motorspeed and hence the output of the blower. r

It will be extend partly through the inlet 25, the construcion andarrangement of the assembly is such that the motor does not undesirablyinterfere with the proper flow of air through this inlet to the'whe'elportion 51. On the contrary, with the motor. wholly supported from theframe 30 and with this frame andthe housing 20 mounted in spacedrelation on their common base 10, the motor and.

inlet 25 define an unobstructed. annular passage '64 through the inletwhich is entirely adequate to provide the proper supply ofair to. thewheel portion 51, and the spaced relation of the frame 30 and housing20, together with the reduced size of flanges 34 towards their upperends, furtherprovide unobstructed access to this annular passage-fromall sides. c I

.This arrangement provides materially improved operation. as contrastedwith conventional blower constructions wherein the supporting shaft forthe blower wheel is mountedhy means of brackets and bearings which ex.-tend radially across the outer end of the inlet. The maximum inward fiowof air takes place around the outer portion ofthe inlet, i. e., in thearea which is nearest to the, blade portions of the wheel, and withconventional constructions wherein the supports for the shaft bracketsextend across these areas of the inlet, these brackets tend to produceundesirable turbulence in the incoming flow of air.- This effect isentirely vabsent from the construc-. tion of; the, present invention,since the inlet 25' has an unobstructed annular passage therethrough atthe areas of. maximum air flow, and the inlet 26 is entirely open. Inaddition, theair entering through the inlet 25 flows along the surfaceof motor 33 andprovides a highly desirable and efiicient cooling effectforthe motor, which is further increased by the provision of ventilationholes 65. in the. frame 3.0 and the bracket 44 which are arranged tocoincide .with the-usual ventilation holes 66 in the me er. i

This construction and arrangement of blower assembly also has theadvantage of being highly compact aswell as simple to fabricate andlight inweight. The overalldimensions of the assembly in height andwidthare. substantially equal to; the corresponding dimensions for the base19 andhous'ing 20 alone, and only a relatively small extensiono the baseis required to provide forthe mountingframe of the motor, Furthermore,since the motor.

and blower wheel are mounted on the base independently e hous ng 20 ands nce both th housing and th otor ar -pro ed wit rubb r cushi ning me rsas. d

sc i ed h e is m imum en en y for r nsmissi n.

ibration bet n he mot r an ho s g. a d h sr flw Wh h f m of appar us v Vstitutes a preferred embodiment of the invention it is to be understoodthat the invenion is not limited to this Precise form at apparat s, anth t cha ge ay b m therein without departing from thescope of theinvention which is defined in the appended claims,

What is claimed is: V l r 1. A blower assembly comprising a dpuble'inletblower housing having inwardly turned annul'ar portions at oppositeside's thereof defining a horizontally aligned pair notedthat eventhough the motor 33 does,

herein described conof inlets, a drive motor for said blower assemblyhaving a drive shaft at one end thereof and including a motor body ofsubstantially smaller diameter than said inlets, a supporting frame forsaid motor including one portion connected to the end of said motor bodyopposite sail drive shaft and a second portion extending lengthwise ofsaid body from said one portion and connected to the other end of saidmotor body, means securing said frame in fixed relation with saidhousing adjacent one of said inlets with said motor and said secondportion of said frame projecting through said one inlet to support saidmotor in cantilevered position within said inlet, a double inlet blowerwheel received in said housing between said inlets and including aninternal partition dividing the interior of said wheel into two partsand leaving both ends of said wheel open to receive, air from therespective said inlets, and a hub secured to said partition and mountedon said drive shaft in close relation with said motor body to supportsaid blower wheel on said drive shaft with a portion of the length ofsaid motor body telescoped within the adjacent one said part of saidwheel.

2. A blower assembly comprising a double inlet blower housing havinginwardly turned and horizontally aligned annular portions at oppositesides thereof defining the inlets thereof, a double inlet blower wheelreceived in said housing between said inlets and including an internalhub structure located intermediate the ends of said wheel to leave bothends of said wheel open for receiving air from the respective saidinlets, a drive motor for said blower assembly having a drive shaft atone end thereof and including a motor body of substantially smallerdiameter than said wheel and said inlets, said hub structure beingmounted on said drive shaft in close relation with said motor body tosupport said blower wheel on said drive shaft with a portion of thelength of said motor body telescoped within the adjacent end of saidwheel and the adjacent said inlet, a supporting frame for said motorincluding one portion connected to the outer end of said motor body anda second portion extending lengthwise of said motor from said firstportion and connected to the inner end of said motor body, and meanssecuring said frame in fixed relation with said housing adjacent saidone inlet and with said motor and said second portion of said frameextending through said one inlet to support said motor and said wheel incantilevered position within said housing.

3. A blower assembly comprising a double inlet blower wheel including aninternal hub structure located intermediate the ends of said wheel toleave both ends of said wheel open for receiving air, a drive motor forsaid blower wheel having a drive shaft at one end thereof and includinga motor body of substantially smaller diameter than said Wheel, said hubstructure being mounted on said drive shaft in close relation with saidmotor body to support said blower wheel on said drive shaft with aportion of the length of said motor body telescoped within the adjacentend of said wheel, a housing for said wheel having horizontally alignedinlets at opposite sides thereof, said wheel being received in saidhousing between said inlets with the outer ends of said motor bodyprojecting outwardly through one of said inlets, a supporting frame forsaid motor including a portion located outside said housing andconnected to said outer end of said motor body, means securing saidframe in fixed relation with said housing adjacent said one inlet andwith said motor body projecting therefrom through said one inlet tosupport said motor and wheel in cantilevered position within saidhousing, and said motor body being of substantially smaller diameterthan said one inlet to provide an annular passage outwardly thereofthrough said one inlet for in-flow of air to said wheel.

4. A blower assembly comprising a double inlet blower housing havinginwardly turned and horizontally aligned annular portions at oppositesides thereof defining the inlets thereof, a double inlet blower wheelreceived in said housing between said inlets and including an internalhub structure located intermediate the ends of said wheel to leave bothends of said wheel open for receiving air from the respective saidinlets, a drive motor for said blower assembly having a drive shaft atone end thereof and including a motor body of substantially smallerdiameter than said wheel and said inlets, said hub structure beingmounted on said drive shaft in close relation with said motor body tosupport said blower wheel on said drive shaft with a portion of thelength of said motor body telescoped within the adjacent end of saidwheel, supporting bracket means for said wheel including a centralportion connected with the inner end of said motor body adjacent saidhub structure and a plurality of angularly spaced bracket arms extendingoutwardly of said wheel generally lengthwise of said motor, and meanssecuring the outer ends of said bracket arms in fixed relation with saidhousing adjacent said one inlet and with said motor and the remainder ofsaid bracket arms extending through said inlet into the interior of saidhousing to form a cantilevered mounting for said motor and said wheel.

5. A blower assembly comprising a double inlet blower wheel including aninternal partition dividing the interior of said wheel into two partsand leaving both ends of said wheel open to receive air, a drive motorfor said blower wheel having a drive shaft at one end thereof andincluding a motor body of substantially smaller diameter than saidwheel, a hub secured to said wheel partition and. mounted on said driveshaft in close relation with said motor body to support said blowerwheel on said drive shaft with a portion of the length of said motorbody telescoped within the adjacent one said part of said wheel,

a housing for said wheel having aligned inlets at opposite sidesthereof, said wheel being received in said housing between said inletswith the outer end of said motor body projecting outwardly through oneof said inlets, a sup porting frame for said motor including one portionconnected to the outer end of said motor body and a second portionextending lengthwise of said body from said first portion and connectedto the inner end of said body, means securing said frame in fixedrelation with said housing adjacent said one inlet with said motor andsaid second portion of said frame extending through said one inlet tosupport said motor and wheel in cantilevered position within saidhousing and to leave the other said inlet substantially unobstructed,said motor body being of substantially smaller diameter than said oneinlet to provide an annular passage for air through said one inlet, andsaid part of said wheel adjacent said motor being of lesser axial lengththan the part of said wheel adjacent said unobstructed inlet to effect asubstantially balanced output throughout the length of said wheel.

References Cited in the file of this patent UNITED STATES PATENTS935,114 Keith Sept. 28, 1909 1,017,215 Ilg Feb. 13, 1912 1,163,543 IlgDec. 7, 1915 1,650,873 Kay Nov. 29, 1927 1,809,603 Reed June 9, 19312,087,160 Meyerhoefer July 13, 1937 2,176,324 Bretzlafi Oct. 17, 19392,316,608 McMahan Apr. 13, 1943 2,375,920 Hewitt May 15, 1945 FOREIGNPATENTS 282,188 Italy Feb. 4; 1931

